The present invention relates to a commercial-grade grinding and mulching machine which is capable of reducing landscape debris such as leaves, grass clippings, brush and small branches to a volume which is usable in developing compost or mulch.
In recent years, the disposal of landscape debris such as leaves, grass clippings, brush and branches has presented major problems. The traditional method of raking such landscape debris into piles and burning it has been curtailed by environmental and clean air concerns. Many communities have severely limited or even totally banned open air burning. Alternatively, such landscape debris has been bagged and transported to neighborhood landfills, but the landfill capacity is constantly shrinking and, in some areas, disposal costs have increased ten-fold.
Landscape debris can also be composted to provide a soil enriching mulch for gardens and landscaping. However, the decomposition of intact leaves, grass clippings, brush and branches is a slow process which can take several years. It is well known that chopping and shredding the landscape debris can substantially reduce its volume and enhance the decomposition process.
A plurality of conventional devices for shredding and composting landscape debris are available. Choppers and shredders of many different sizes and configurations are being marketed by a variety of manufacturers. These choppers and shredders generally include a chute or hopper for introducing the debris to be chopped or shredded into a chamber which includes a plurality of knives and/or hammers which chop and/or pulverize the debris. Often the chamber is surrounded by a mesh screen with holes in the mesh sized to pass the desired particle size of the chipped and pulverized debris. The debris is circulated within the chamber until it is chopped and/or pulverized to a size which will pass through the screen.
Prior art chippers and shredders have a single chamber which is used for cutting and pulverizing the introduced debris. This arrangement requires debris to be introduced directly into the pulverizing chamber at a relatively high velocity. This means that debris being introduced into the chamber impacts with debris which is circulating within the chamber, thus disturbing the efficient circular flow of the material circulating within the chamber and reducing the efficiency of the chipper or shredder. Furthermore, many conventional machines introduce material near the periphery of a circular chamber where the velocity of the recirculating material within the chamber is at its greatest. This increases the interference effect between the debris being introduced and the debris being recirculated.
It is clear then, that a need exists for a landscape debris grinding and mulching machine which can introduce and process large volumes of landscape debris in a rapid and efficient manner.